*Holley Truck Avenger carb* From what it looks like to me, it appears to be a "standard" Holley 650 carb with some modifications that are pretty dawg-awn cool! This shot (and the pics that follow it) clearly show the Annular Boosters. The restrictive (but better) primary booster design is probably why this carb is rated at 625 CFM and not 650. All-though I doubt the boosters restrict the air flow that much. Detailed pics of the "modified" Metering Block -vs- A Stock Block. Main Body to Metering Block Metering Block to Main Body Metering Block to Float Bowl Holley Truck Avenger carb album.